R.I. Gen. Laws § 34-26-3: Methods of discharge.

A mortgage may be discharged in whole or in part by an entry acknowledging the satisfaction thereof or the payment thereon, as the case may be, made on the face or back of the mortgage, or upon the face or margin of the record of the mortgage, in the records of land evidence, and signed by the mortgagee or by his or her executor, administrator, successor, or, if the mortgage be assigned, by the assignee or his or her executor or administrator; and such entry shall have the same effect as a deed of release duly acknowledged and recorded.